烟草秸秆纳米纤维素的制备及表征分析

Preparation and Characterization of Nanocellulose from Tobacco Straw

为有效利用农业废弃物烟草秸秆(TS),以TS为原料,用超声波辅助硫酸法制备纳米纤维素(CNC),并对所得产物进行光学显微镜观察、场发射扫描电镜分析、傅里叶红外光谱分析、X-射线衍射分析、热重分析和流变分析。结果表明,TS与64%的浓硫酸料液比1∶15(g∶mL)在45℃条件下反应60 min,CNC的产率为22.4%;制备的CNC为短棒状结构,直径为10~20 nm;X-射线衍射分析表明,其仍然为纤维素Ⅰ型结构,相对结晶度为58.5%;CNC具有较好的热稳定性,起始热解温度为252.36℃;稳态流变测试表明,TS-CNC悬浮液黏度随固含量增加而升高,剪切变稀行为随黏度增加而增强;动态应变测试表明,TS-CNC悬浮液在固含量为1.00%时,表现出凝胶行为。

In order to effectively utilize agricultural waste tobacco straw(TS),TS was used as raw material,cellulose nanocrystal(CNC)was prepared by ultrasonic assisted sulfuric acid method.The products were observed by optical microscope,scanning electron micrograph,FT-IR spectra,X-ray diffraction(XRD),thermogravimetric(TG)and rheological analysis.The results showed that the yield of CNC was 22.4%when the ratio of TS to 64%sulfuric acid was 1∶15(g∶mL),and the reaction time was 60 min at 45℃.The prepared CNC was short rod-like structure with a diameter of 10—20 nm;XRD analysis showed that it retained natural celluloseⅠstructure with a relative crystallinity of 58.5%;CNC had better thermal stability,and the initial pyrolysis temperature was 252.36℃.The steady-state rheological test showed that the viscosity of TS-CNC suspension increased with the increase of solid content,and the shear thinning behavior strengthened with the increase of the viscosity.The dynamic strain test showed that CNC suspension solution exhibited obvious gel behavior when the solid content was 1.00%.